A vehicle system, such as an automatic driving system, may monitor a physical state of a driver to determine whether a vehicle may be operated in a manual driving mode or an autonomous driving mode. For example, the automatic driving system may use physical observations, e.g., cameras, to assess driver behavior and accommodate for a slow reaction time, attention lapse, drowsiness, intoxication, etc. When the automatic driving system determines that a driver is exhibiting slow reaction times, attention lapses, drowsiness, intoxication, etc., the automatic driving system may modify operation of one or more of the vehicle systems. The driving system, however, may not account for risks that a driver may be willing to take based on a current mental state, as observed through brainwave activity.